Cats are mysterious creatures. It is said that they do what pleases them. Haley Berry in the movie 'Cat Women', says, "cats come when they feel like, not when they are told." This statement pretty much sums up feline personality. So when and why do cats change their heating habits, is it an illness or just something they feel like? Loss of Appetite A cat doesn't eat in two instances: One, it can be a sign of an illness, and two, it can be a natural process. Cats are primarily hunters, so as the law of nature goes, cats and birds have an inbuilt system of changing their diet from time to time. This happens to avoid dependence on one food source. If this is the case, your cat will be just nibbling at the food in the bowl but will also be meowing for something different. Another reason could be that there is plenty of prey available for it, so chances are that she has been feeding on rats and birds. These reasons are nothing to worry about, as your kitty will be back to its normal self in no time. On the other hand, if you notice some other changes in your cat's behavior along with a loss in appetite, then watch for symptoms of diseases. Certain health problems like worms, fleas and cold can be some less worrisome reasons for loss of appetite in cats. Other problems like respiratory illnesses, issues with digestion like a inflammatory bowel disease, twisted bowel, cancer and diarrhea are some serious issues that only a vet can diagnose. Appetite Stimulant If you are wondering how to increase the appetite of a cat, then don't worry, it is relatively easy. You can try to entice the cat to eat by tempting it with its favorite food. Use good smelling food like tuna and sardines, as this will stimulate the cat's taste buds. There are also some natural appetite stimulants, for example catnip and you could also increase the vitamin B intake in the cat food. Give the cat plenty of egg and milk, also make sure that the cat is well hydrated. You can also opt for prescription drugs suggested by your vet as an appetite stimulant. Also try to get the cat to hunt, this will increase her interest in food and kick in its natural instinct. Increase in Appetite In aging cats, a condition known as polyphagia is responsible for an increase in appetite. Diabetes, hyperthyroidism and pregnancy are other reasons for increase in the appetite. Cushing's disease is another rare reason for an increase in appetite. Only proper diagnosis made by a vet can ascertain these as the cause. Another reason for cats to overeat can be worms, therefore, check if she has worms. If you think your cat is overeating, you can regulate her diet by reducing the meal quantity. Many times, the owner fills the bowl with enough food to last the day. Most cats regulate their own diet, but some of them who fail to do so tend to become overweight. For this, you will have to reduce the amount of cat food you put in the bowl. Appetite Suppressant Per se, there aren't any approved appetite suppressants. The only way to deal with an obese cat is to be tough and regulate her meal timings, and make sure that she is on a proper diet. Avoid giving it human snacks. Give your cat a course of de-worming and try to keep her active. Remember, a change in appetite is not always due to an illness; at times, it's just nature running its course. Do visit the vet if you witness other changes in your cat, or spot some symptoms that suggest a disease. Remember, when it comes to pets, trust your instinct.